There are more important matters we need to discuss. (Longman Dictionary)
It was a personal matter , and she had no intention of talking to any journalist about it. (Longman Dictionary)
She held strong views on religious matters . (Longman Dictionary)
The legal arrangements for the sale are matters for negotiation . (Longman Dictionary)



Maybe some of these suggestions will help to improve matters. (Longman Dictionary)
His long absences didn't help matters (=made the situation worse) . (Longman Dictionary)
The team has lost the last two games and, to make matters worse, two of its best players are injured. (Longman Dictionary)



They feed mostly on decaying vegetable matter. (COBUILD Dictionary)
waste matter from industries (COBUILD Dictionary)
elimination of waste matter from the body (Oxford Dictionary)
Add plenty of organic matter to improve the soil. (Oxford Dictionary)



生死攸關=a matter of life and/or death

The quality of the ambulance service is a matter of life and death. (Longman Dictionary)
Can't it wait? It's hardly a matter of life or death, is it? (Longman Dictionary)


見仁見智=be a matter of opinion

Whether or not he is any good as a manager is a matter of opinion. (Longman Dictionary)
Many of these answers are
a matter of opinion; some issues will matter more to some people than others. (Longman Corpus)


這是個人喜好問題=be a matter of (personal) taste/choice/preference

I can't say which wine is best - it's a matter of personal taste. (Longman Dictionary)


這是原則問題=be a matter of principle

She couldn't take the money. It was a matter of principle. (Longman Dictionary)


程序上要做的/理所當然=as a matter of course/routine

We will contact your former employer as a matter of course. (Longman Dictionary)
We always check people's addresses
as a matter of course. (Oxford Dictionary)